The 31-year-old Ram won his only other career finals he has played, in Newport in 2009 and last year. He beat Querrey in '09 to claim his first tour-level title.
"I felt calm from the start because I had a game plan going in to make sure I was on the offensive," said Ram, who -- regardless of what happens in the final -- will rise to a career-high ranking in the top 70. "I didn't want to let him set his feet too much. I wanted to take the first strike before he did. I do not need to be running side to side chasing his forehand."
After admitting to a bout of nerves during his three-set quarterfinal win over Benjamin Becker, the 31-year-old Ram played what he called "two of the best sets of tennis I've ever played."
Ram played composed, controlled tennis, mixing up powerful forehands and big serves with well-timed forays to the net. He took advantage of a bevy of unforced errors by Dimitrov, particularly off the backhand side. Ram broke Dimitrov in the first game of the match and then again in the third game of the second set. He never faced a break point on his own serve and won on his second match point when Dimitrov dumped a forehand return into the net.
"It wasn't my best, best day today," Dimitrov said. "I was trying everything, serve and volley, slice, trying to attack. But everything went his way and absolutely nothing was going my way."
The match was disrupted briefly in the second set when chair umpire Simon Cannavan spotted a drone flying high over the court. During the US Open last year, a drone crashed into the stands during a match between Flavia Pennetta and Monica Niculescu.
Querrey never faced a break point against del Potro and lost just nine points on serve, including two in the second set. Both sets were identical in that neither player blinked until the 11th game when Querrey broke and then held serve.
"That was definitely the best I've played so far," said Querrey, who served 10 aces to del Potro's five. "I served great and it allowed me to claw myself in until I could break him."
Del Potro, the 2009 US Open champion who was playing in his first tournament in 11 months due to two surgeries on his left wrist last year, used a mix of one- and two-handed backhands, as well as his customarily potent forehand. But his fatigue after playing four matches -- the same number he played in all of last year -- was evident.
"I think this week I more than won the tournament," said del Potro, who confirmed that he will be playing the BNP Paribas Open in Indian Wells next month. "There are so many positive things. I'm looking forward to the future because I can make a plan for playing tournaments."